(Adds details on fitness routine, life as ex-president)
By Karen Brooks
DALLAS, Aug 6 (Reuters) - Former President George W. Bush, 67, a fitness enthusiast whose presidency was shaped by the attacks on Sept. 11, 2001, underwent successful surgery at a Dallas hospital on Tuesday to place a stent in a blocked heart artery.
Doctors discovered the blockage on Monday during Bush's annual physical at the Cooper Clinic in Dallas, according to a statement from spokesman Freddy Ford.
Doctors recommended a stent to open the blockage, and he underwent surgery on Tuesday morning at Texas Health Presbyterian Hospital, the statement said.
The former president was "in high spirits, eager to return home tomorrow and resume his normal schedule on Thursday," Ford said.
Bush was known as a fitness enthusiast during his two terms in the White House, from 2001 to 2009, and liked to run before knee pain led him to do more bicycling.
Since leaving the White House, Bush has participated three times in the 100-kilometer (62-mile) Warrior 100K bike ride along with 20 wounded military veterans.
As president, he introduced the Adult Fitness Challenge and the Presidential Active Lifestyle Award. The website AskTheTrainer.com named him the most physically fit president in U.S. history.
"I love exercise," Bush said in a video for Physical Fitness Month in 2007. "The message to all Americans is to find time in your schedule to walk, swim, bike, take care of yourself."
His father, George H.W. Bush, served as president from 1989 to 1993. Now 89, the elder Bush spent seven weeks in a Houston hospital for bronchitis and related ailments before his release on Jan. 14. He often makes public appearances in a wheelchair.
The younger Bush left office in January 2009 with low public approval ratings due to the U.S. financial crisis that erupted near the end of his second term, and the unpopular war in Iraq.
But a Gallup poll in June showed 49 percent of respondents viewed him favorably versus 46 percent unfavorably, the first time since 2005 that opinions of him were more positive than negative.
Bush's presidency was influenced by the attacks of Sept. 11, 2001, which led him to send U.S. forces to invade Afghanistan and then Iraq. The subsequent years of combat in Iraq divided the United States and cost thousands of lives and hundreds of billions of dollars.
Bush was in Africa last month when he joined his successor Barack Obama in Tanzania at a ceremony marking the 15th anniversary of an al Qaeda attack on the U.S. Embassy there that killed 10 Tanzanians and injured 85 Americans and Tanzanians.
Bush had maintained a lower profile during Obama's first term, saying a former president should avoid creating distractions for his successor.
He returned to the spotlight in April, when Obama and three surviving former presidents dedicated Bush's presidential library in a ceremony in Dallas. (Reporting by Jim Forsyth in San Antonio, Karen Brooks in Dallas and Steve Holland in Washington; Writing by Daniel Trotta; Editing by Bill Trott and Philip Barbara)